Combustion chamber



March 25, 1958 A. D. MODUFFIE ETAL 2,327,392

COMBUSTION CHAMBER- Filed Dec. 19, 1956 2 Sheets-Sheet],

v 'ATTORNEY March 25,1958 A. D. M DUFFI E ETAL 2,827,892

COMBUSTION CHAMBER 7 Filed Dec. 19, 1956 2 Sh ee ts-Sheet 2 United States Patent COMBUSTION CHAMBER Archie D. McDufiie, Berkley, and Floyd A. Wyczalek,

Birmingham, Mich., assignors to General Motors Corporation, Detroit, Micln, a corporation of Delaware Application Decemberlil, 1956, Serial No. 629,359 7 Claims. (Cl. 123-9191) This invention relates to combustion chambers for the cylinders of internal combustion engines. The invention is an improvement on the combustion chamber now be ing employed in Buick V-8 engines, this being specifically described and illustrated in application Serial No. 320,518 filed inrthe name of Joseph D. Turlay, November 14, 1952.

It is proposed to increase theburn rate and to decrease the time required to burn in the Buick combustion chamber, This is accomplished by decreasing the flame travel in the firing chamber, by increasing the squish area and turbulence and by dividing the firing chamber into two relatively compact parts, each provided with ignition means for initiating the burning of fuel in each part. With such a construction the combustion chamber embraces what amounts to two relatively small and compact firing chambers and a relatively large clearance space in which the last part of the charge burns slowly from the two parts of the firing chamber in which burning of the charge is initiated.

In the drawings:

Figure 1 is a fragmentary vertical sectional view through an engine cylinder embracing the invention. Across the cylinder and piston the view is taken on a diameter of the cylinder. Across the head the view is taken substantially in the plane of line 1--1 on Figure 2, looking in the direction of the arrows thereon.

Figure 2 is a fragmentary plan view of the engine head embodied in the structure disclosed by Figure 1. Figure 2 is taken substantially in the plane of 2-2 of Figure 1, looking in the direction of the arrows thereon.

Figure 3 is a fragmentary vertical sectional view of the cylinder illustrated by Figure 1 except that in the head the view is taken substantially in the plane of 33 on Figure 2, looking in the direction of the arrows there- Figure 4 is a fragmentary cross sectional view of the engine cylinder illustrated by the preceding figures and taken substantially in the plane of 44 on Figure 3. Figure 4 particularly illustrates the configuration of the piston embodied in the engine cylinder disclosed by Figures 1 and 3.

The engine 10 embodying the invention comprises a 7 cylinder 11 in which a piston 12 reciprocates between inner and outer dead center positions, the outer end of the cylinder being closed by a head 13 removably secured to the cylinder by bolts 14. The head has an inner wall 16 in which a combustion chamber cavity 17 is formed by side wall means 18 and 19 and end wall means 21. The side wall means 18 and 19 merge at the adjacent edges thereof in an elongated arcuate wall section indicated at 22, the side wall means 18 and 19 being walls with substantially plane inner surfaces disclosed obliquely to the axis of the cylinder 11 and intersecting the ends of the cylinder on substantially parallel cords. The side wall means 18 and 19 are disposed substantially at 90 to one another to facilitate manufacture of the engine and to make the cavity 17 as compact as possible. The

inlet and exhaust valves 23 and 24 for the cylinder 11 may open throughthe wall 19 it this is desired, or the valves may be arranged in any other desired relation. The piston 12 has anend wall 25 which may be formed to provide a projection indicated at 25. The projection embraces side wall means 27 parallel to the side wall means 19 and side wall means 28 parallel to the side wall means 18. The projection also has end walls 29 which are substantially parallel to the end wall 21 of the cavity 17. When the piston 12 is in outer dead center position in the cylinder 11 the surfaces of the head and the piston form minimum mechanical clearance spaces 31 and 32 between the end wall 25 of the piston and the inner wall 16 of the head, and between the side wallmeans 27 of, the piston and the side wall means 19 of the head. The wall 28 of the piston is spaced from and substantially parallel to the side wall means 18 of thecavity 17 to provide a firing chamber indicated at 33. It will be noted that the wall 27 covers a substantial part of the surface of, the side wall means 19 and the inlet and exhaust valves 23 aud24 and closely approaches the side wall means 18 to reduce the depth of the firing chamber 53 throughout the length thereof. If desired theprojection 26 may be extended adjacent the piston 12 and" toward the side wall means 18 by providing walls 34 and 36. Wall 34 may be variably located with respect to the end wall 25 of the piston 12 to vary the compression ratio in the cylinder. The wall 36 is spaced from the inner edge of the side wall means 18 to provide an additional minimum mechanical clearance space indicated at 37.

It will be noted from the drawing that the firing chamber 33 is elongated and relatively shallow and extends substantially entirely across a diameter of the cylinder 11 in opposed relation to the inlet and exhaust valves 23 and 24. It will be noted from examining Figure 2 that the firing chamber 33 may be divided into two substantially equal end parts which are relatively compact and the depth of which is substantially equal to one-half the width thereof in any direction.

It is proposed to place the spark plugs in the side Wall means 18 substantially at the middle of each of these end parts. The spark plug 38 is therefore located in the side wall means 18 substantially opposite the inlet valve 23 and the spark plug 39 is similarly located in the side wall means 18 substantially opposite the exhaust valve 24. The positions of the terminals 41 of the spark plug means are such as to be substantially in the central parts of the end parts of the firing chamber 33. The valves and spark plug means for the cylinder 11 are operated in timed relation to the piston so that when the piston approaches the outer dead center position in the cylinder the spark plugs 38 and 39 will ignite the compressed charge in the firing chamber 33 in two places and at the terminals 41. The compressed charge will burn in all directions from the ignition terminals 41 and the burning in each end of the firing chamber will consume all of the compressed charge in the firing chamber 33 at substantially the same time and in a greatly decreased amount of time. After the charge is burned in the firing chamber 33 the burning will continue in the relatively shallow clearance spaces 31, 32 and 37 at a slower rate.

We claim:

l. A combustion chamber for engines comprising a cylinder having a head and a piston, said head having an inner wall formed to provide an elongated cavity ex tending across the end of said cylinder, said inner wall being formed to provide side wall means and end wall means for said cavity, inlet and exhaust valves opening into said cavity through said side wall means, a pair of spark plugs opening into said cavity through said side wall means, each of said spark plugs being directly opposed to one of said valves and opening into said cavity substantially at the middle of each end of said cavity.

2. A combustion chamber for engines comprising a cylinder having .a head and a piston, said head having an inner Wall formed to provide an elongated cavity extending across the end of said cylinder, said inner Wall being formed to provide side Wall means merging at the edges thereof to form sides of said cavity disposed obliquely to the axis of said cylinder, inlet and exhaust valves opening into said cavity through said side wall means, a pair of spark plugs opening into said cavity through said side wall means, each of said spark plugs being directly opposed to one of said valves and opening into said cavity substantially at the middle of each end f said cavity. 7

3. A combustion chamber for engines as defined by claim 2 and in which said valvesare in one of said side wall means and said spark plugs are in the other of said side wall means.

4. A combustion chamber for engines as defined by claim 3 and in which each of said side wall means has substantially a plane inner surface through which said valves and said spark plugs open.

5. A combustion chamber for engines, comprising a cylinder having a head and a piston, said head having an inner wall formed to provide an elongated cavity extending across the end of said cylinder, said inner wall 1 and the adjacent end of said piston being formed to provide parallel pairs of side wall means merging at the edges thereof to form sides of said cavity disposed obliquely to the axis of said cylinder, inlet and exhaust valves opening into said cavity through said side wall means of said head, spark plug means opening into said cavity through said side Wall means of said head, said side wall means of said headand said piston being spaced between a parallel pair of said side wall means at one side of said cavity to provide firing chamber means into which explosive charges may be compressed adjacent said spark plug means.

6. A combustion chamber for engines as defined by claim 5 and in which said spark plug means is a pair of spark plugs, each of said spark plugs being directly opposed to one of said valves and opening into said cavity substantially at the middle of each end of said cavity.

7. A combustion chamber for engines as defined by claim 5 and in which said side wall means on said piston forms a projection extending into said cavity on the side of said. cavity adjacent said valves and remote from said spark plug means.

References Cited in the file of this patent UNITED STATES PATENTS 

